Intracranial aneurysms represent a difficult to detect cause of morbidity and mortality. Detecting intracranial aneurysms is very important in preventing severe morbidity or death. Although digital subtraction angiography (DSA), which is an invasive method, is considered the gold standard in detecting intracranial aneurysms, non-invasive 3D time-of-flight magnetic resonance angiography (hereinafter referred to as MRA) is often used as a screening tool because it is less costly and present less risk to the patient.
A typical MRA dataset usually contains more than 100 images, making it very time-consuming for radiologists to review the dataset and determine whether any aneurysms are present. Furthermore, small aneurysms are often likely to be missed by radiologists using current analysis methods such as reviewing maximum intensity projection (MIP) images. This is because adjacent vessels or unusual locations may be overlapped on MIP images of MRA. With MIPs, even for experienced radiologists, the sensitivity to small (<5 mm) aneurysms in MRA images is only in the range of 35 to 60%.